I bought these 4-2-1 headers a while back ago and they have the O2 sensor valve on the #1 exhaust pipe. I never got them installed because this guy that i got it from told me they would work on the D16 engine, but the O2 sensor for my 99 Ex is pre-cat location rather then the exhaust header location.

I'm moving out and trying to sell them, but haven't figured out what application the Headers are for!

their DC sports ceramic...

 

I bet you got them off ebay and they are not a DC-Sport header... I am sure they are DC-Style which is a totally different thing... It looks like dc but its not.

 

i got them off a guy on craigslist.
they looked like the same application, but i found out later the o2 sensor was in a different location [:@]

but they have the CARB certs welded on n everything.